That person, normally a female, who defines everything that warrents your scorn. This term should only be said to the person it describes if you know you will never want anything from her (or him), including, but not limited to, sex, booze, sex with her sister or friend.

That Marissa Walch is such a Motherfucking Piece of Shit Dumbass Bitch Whore and she should be shot.